title: MR elastography derived shear stiffness--a new imaging biomarker for the assessment of early tumor response to chemotherapy.
abstract: OBJECTIVE
  The overall goal is to develop magnetic resonance elastography derived shear stiffness as a biomarker for the early identification of chemotherapy response, allowing dose, agent type and treatment regimen to be tailored on a per patient basis, improving therapeutic outcome and minimizing normal tissue toxicity. The specific purpose of this study is to test the feasibility of this novel biomarker to measure the treatment response in a well-known chemotherapy model.
  
  
  METHODS
  Tumors were grown in the right flank of genetically modified mice by subcutaneous injection of DoHH2 (non-Hodgkin's lymphoma) cells. Magnetic resonance elastography was used to quantify tumor stiffness before and after injection of a chemotherapeutic agent or saline. Histological tests were also performed on the tumors.
  
  
  RESULTS
  A significant decrease (P < 0.0001) in magnetic resonance elastography-derived tumor shear stiffness was observed within 4 days of chemotherapy treatment, while no appreciable change was observed in saline-treated tumors. No significant change in volume occurred at this early stage, but there were decreased levels of cellular proliferation in chemotherapy-treated tumors.
  
  
  CONCLUSIONS
  These results demonstrate that magnetic resonance elastography-derived estimates of shear stiffness reflect an initial response to cytotoxic therapy and suggest that this metric could be an early and sensitive biomarker of tumor response to chemotherapy.
authors.affiliation: Department of Biomedical Engineering, Mayo Graduate School, Rochester, Minnesota, USA.
authors.forename: Kay M
authors.initials: KM
authors.lastname: Pepin
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Glaser
authors.forename: Yogesh K
authors.initials: YK
authors.lastname: Mariappan
authors.forename: Brian
authors.initials: B
authors.lastname: Reuland
authors.forename: Steven
authors.initials: S
authors.lastname: Ziesmer
authors.forename: Rickey
authors.initials: R
authors.lastname: Carter
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Ansell
authors.forename: Richard L
authors.initials: RL
authors.lastname: Ehman
authors.forename: Kiaran P
authors.initials: KP
authors.lastname: McGee
mesh_terms: D000818:Animals; D015415:Biomarkers; D045744:Cell Line, Tumor; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology*; D008297:Male; D051379:Mice; D016513:Mice, SCID; D008822:Mice, Transgenic; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength; D013314:Stress, Mechanical; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers
keywords: MR elastography; cancer stiffness; chemotherapy response; individualized medicine